Consider the numerical pyramid below, formed by simply putting down the series of odd numbers into a pyramid.
1
3 5
7 9 11
13 15 17 19
. . .
Find a formula for the sum of the numbers in the nth row, and prove it.
(In reply to
sk, i dnt understand quite what u r getting at by anand)
Anand,
You wrote:
, the number of odd numbers that would have been used up is given by 1+2+3+4....n-1 i.e n(n-1)/2 ..
__________
You used the generic formula n(n-1)/2. This is true... but you didn't prove it. Neither did I initially. Charlie called me on it, so I did.
re: sk, i dnt understand quite what u r getting at
